A randomized trial of calorie labeling on menus

Abstract

Background: Food consumed outside the home accounts for a growing proportion of the North American diet and has been associated with increased obesity.

Purpose: To examine the effect of nutrition labeling on menus on awareness, use, and food consumption, including the impact of "traffic light" labeling and adding other nutrients.

Methods: Blinded, randomized trial with 635 Canadian adults conducted in 2010-2011. Participants ordered a free meal from one of four experimental menus: 1) no nutritional information shown, 2) calorie amounts only, 3) calorie amounts in "traffic lights", and 4) calorie, fat, sodium, and sugar shown in "traffic lights". Recall of nutrition information, knowledge of calorie content and nutrient consumption were assessed.

Results: Participants in the calorie conditions were more likely to recall the calorie content of meals and to report using nutrition information when ordering. The calorie content of meals was not significantly different across conditions; however, calorie consumption was significantly lower among participants in the Calorie-only condition compared to the No information condition (mean=-96 kcal, p=.048).

Conclusions: Menu labeling increased awareness and use of nutrition information and reduced consumption. Adding "traffic lights", fat, sodium, and sugar amounts to menus had little impact compared to calorie-only labeling.

Trial registration: ClinicalTrials.gov NCT01948752.

Keywords: Diet; Food labeling; Health behavior; Nutrition policy; Obesity.